Metal-clad switchgear



June 21, 1949. CHUBBUCK 2,473,861

METAL-GLAD SWITCHGEAR Filed June 15, 1946 myz.

9 La l WITNESSES: INVENTOR Leohard 5. 671a bbuc/r.

ATTOR Y ZXZM WWW L Patented June 21, 1949 METAL-GLAD SWITCHGEAR LeonardB. Chubbuck, Hamilton, Ontario, Canada, assignor to WestinghouseElectric Corporation, East Pittsburgh, Pa., a corporation ofPennsylvania Application June 15, 1946, Serial No. 676,895

3 Claims.

My invention relates, generally, to metal-clad switchgear, and, moreparticularly, to devices for lifting the circuit breakers into theoperating position in the switchgear cells.

In metal-clad switchgear of the vertical lift type, it is customary toraise the circuit breakers into a position where the breaker bushingsmake contact with connections to the bus bars which are located abovethe circuit breakers. This work has previously been done by hand ormotor operated mechanical devices which are somewhat complicated andexpensive.

An object of my invention, generally stated, is to provide a liftingdevice for metal-clad switchgear which shall be simple and efficient inoperation and which may be economically manufactured and installed.

A more specific object of my invention is to provide a fluid-pressureoperated lifting device for metal-clad switchgear.

Another object of my invention is to provide for individuallycontrolling the operation of a plurality of fluid-pressure operatedlifting devices for metal-clad switchgear.

Other objects of my invention will be explained fully hereinafter orwill be apparent to those skilled in the art.

In accordance with one embodiment of my invention, a fluid-pressureoperated device is provided in each one of a plurality of switchgearcells for lifting the circuit breakers to their operating position. Theoperation of the devices is so controlled that each breaker may beraised and lowered independently of the other breakers. All of thedevices are supplied with fluid by a single pressure pump which isconnected to the devices through control valves.

For a better understanding of the nature and objects of my invention,reference may be had to the following detailed description, taken inconjunction with the accompanying drawing, in which:

Figure l is a view, in front elevation, of metalclad switchgearembodying the principal features of my invention, and

Fig. 2 is a view, in side elevation, of the structure shown in Fig. 1.

Referring to the drawing, particularly to Fig. 1, the structure showntherein comprises two metalclad switch-gear cells of the usual typehaving a circuit breaker unit ll disposed in each cell. The circuitbreakers are of the vertical lift type, each breaker having contactmembers 12 disposed to engage cooperating contact members 13 which areconnected to bus bars located in a 2 compartment I4 above the circuitbreakers. It will be understood that additional cells may be provided.

In accordance with the usual practice, a breaker unit may be wheeledinto a cell on a truck I5. The breaker is then raised vertically to itsoperating position in which the contact members 12 and I3 are fullyengaged. Since the breakers are relatively heavy, it is necessary toprovide a lifting device of some type to raise and lower the breakers inthe cells It]. The lifting devices previously utilized have been of amechanical type, such as lifting screws which are either hand or motordriven through gears and chains.

In order to simplify the elevating mechanism for the circuit breakerunits, I have devised a fluid-pressure operated device in which theoperating medium may be either a liquid, such as oil, or a gas, such ascompressed air. As shown, in the floor of each cell is located ahydraulic lift I6 capable of raising or lowering the breaker H throughthe necessary travel.

A fluid reservoir H, a suitable pump and check valve l8, a motor IQ fordriving the pump, and a combined excess pressure release valve andelectrically operated discharge valve 2i are located at one end of thestructure. The pump 18 and the valve 2| are connected to a header pipe22 which extends along the rear of the cell structure. Standard valves23 control the flow of fluid between the header pipe 22 and theindividual lifts IS. A pipe 24 connects each valve 23 to the bottom ofits lift. A hand wheel 25 is located at the front of each cell and isconnected to the valve 23 at the rear of the cell by a rod 26.

A standard double-make push-button switch 21 is located on the face ofeach cell Ill. The top or Raise button connects the motor [9 across apower source, causing the pump l8 to build up pressure in the headerpipe 22. The bottom or Lower button connects the discharge valve 2|across the power source, thereby venting the header pipe 22 into thereservoir II.

To raise any breaker, its respective valve 23 is first opened by turningthe proper'handwheel 25. The Raise push button for the breaker is heldclosed until the breaker is raised to its operating position. The fingeris then removed from the push button and supporting pins 28 put in placeunderneath shoulders 29 on the breaker tank to hold the breaker in itselevated position.

The Lower button is then pressed to allow the lift plunger to drop ashort distance to release an interlock (not shown) which prevents thebreaker from being closed while it is being raised or lowered in thecell. Other standard forms of interlocking may be utilized if desired.The valve 23 is then closed, thereby retaining the lift plunger almostfully elevated. Guide members 3| may be provided on the sides of thebreaker tank to keep it located properly in the cell while being raisedor lowered.

To lower any breaker, its valve 23 is opened and its Raise buttonpressed to raise the breaker tank oil the supporting pins 28. The pins28 are removed and the Lower button held closed until the breaker islowered onto the truck IS. The valve 23 is then closed.

In case the Raise push button switch is closed after an operation iscompleted, pressure will be built up in the system but the excesspressure release valve Will open to thereservoir I! to prevent thepressure from becoming dangerous. It will be noted that pressure isapplied to the system during only a short time during each operation. Ifdesired, the system may be converted from hydraulic to compressed air bysubstituting a compressor for the pump I 8.

From the foregoing description, it is apparent that I have provided alifting device for switchgear which is simple, eificient and safe inoperation. Provision is made for individually controlling the operationof any one of a plurality of lifting devices which are connected to thesame source of pressure fluid.

Since numerous changes may be made in the above-described constructionand different embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all mattercontained in the foregoing description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

I claim as my invention:

1. In a metal-clad switchgear, in combination, a plurality of cellstructures, a circuit breaker for each cell, a fluid-pressure device ineach cell for raising the circuit breaker in that cell, a single headerpipe for supplying pressure fluid to all of the devices/an individuallyoperable valve for connecting each device to the header pipe, a singledischarge valve for releasing the pressure fluid from the header pipe,and individually operable electrical control means associated with eachcell for controlling the operation of the discharge Valve.

2. In metal-clad switchgear, in combination, a plurality of cellstructures, a circuit breaker for each cell, a fluid-pressure device ineach cell for raising the circuit breaker in that cell, a single headerpipe for supplying pressure fluid to all of the devices, an individuallyoperable valve for connecting each device to the header pipe, pump meansfor creating fluid pressure in the header pipe, a single discharge valvefor releasing the fluid pressure from the header pipe, and individuallyoperable electric switches associated with each cell for controlling theoperation of said pump means and said discharge valve.

3. In metal-clad switchgear, in combination, a plurality of cellstructures, a circuit breaker for each cell, a fluid-pressure device ineach cell for raising the circuit breaker in that cell, a single headerpipe for supplying pressure fluid to all of the devices, an individuallyoperable valve for connecting each device to the header pipe, means forcreating fluid pressure in the header pipe, a single discharge valve forreleasing the fluid pressure from the header pipe, and individuallyoperable electrical control means associated with each cell forcontrolling the operation of said means for creating fluid pressure andsaid discharge valve.

LEONARD B. CHUBBUCK.

REFERENCES CITED The following referenlces are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,873,787 Rankin Aug. 23, 19321,878,999 Ainsworth Sept. 27, 1932 1,889,269 Woodbury Nov. 29, 1932-1,928,460 Paxton Sept. 26, 1933 1,975,278 Lebel Oct. 2, 1934 2,058,377Francis Oct. 20, 1936 2,169,481 Sillers et a1. Aug. 15, 1939

